Oil derrick erection and support system



Dec. 16, 1969 N. D- DYER ETAL OIL DERRICK ERECTION AND SUPPORT SYSTEMFiled Nov. 24, 1967 5 Sheets-Sheet 1 2 INVENTORS NC'RMAN I EVER EURTON/14 FEEENCfw Dec. 16, 1969 N. D. DYER ETAL 3,483,933

OIL DERRICK ERECTION AND SUPPORT SYSTEM Filed Nov. 24, 1967 5SheetsSheeT 2 Dec. 16, 1969 N. D. DYER ETAL 3,483,933

OIL DERRICK ERECTION AND SUPPORT SYSTEM Filed Nov. 24, 1967 5Sheets-Sheet 3 Dec. 16, 1969 N. D. DYER ETAL 3,433,933

OIL DERRICK ERECTION AND SUPPORT SYSTEM Filed Nov. 24, 1967 5Sheets-Sheet 4 FIG. 9

Dec. 16, 1963 N. D. DYER ETAL 3,483,933

OIL DERRICK ERECTION AND SUPPORT SYSTEM Filed Nov. 24, 1967 5Sheets-Sheet United States Patent 0 I 3,483,933 OIL DERRICK ERECTION ANDSUPIORT SYSTEM Norman D. Dyer and Burton W. French, Beaumont, Tex,assignors to Dresser Industries, Inc, Dallas, Tex a corporation ofDelaware Filed Nov. 24, 1967, Ser. No. 685,665 Int. Cl. EZlc 9/00,11/00; 1866c 23/60 US. Cl. 173-39 12 Claims ABSTRACT OF THE DISCLOSURE Areclining oil well derrick mast is coupled at a pivot to a base andextends away from the base along the ground. An A-frame is mounted onthe base rearward of the pivot and supports spaced apart pulleys at alevel above the pivot. Three additional pulleys are spaced along eachside of the mast. A cable is anchored at each end to the A-frame and isthreaded over the topmost of the pulleys on the mast and thence to thepulleys on the A- frame. The cable then passes to the middle pulley onthe mast and thence to the lowermost pulley and then to a travelingblock which is movable from the lower extremity of the mast to the crownblock for erection of the mast in one traverse of the traveling block.Set-back structure is connected to the A-frame independent of the mastto support a rotary table below the traveling lock.

FIELD OF THE INVENTION This invention relates to oil well drillingapparatus of extended height, and more particularly to a system for theerection and support of the mast, associated structure and mechanicalequipment. In a further aspect, the invention involves a structure inwhich a roatry table is isolated from the mast, with arrangement for theconvenient erection and assembly of drilling system components.

THE PRIOR ART It has become necessary for the oil well drilling industryto utilize extremely tall masts and high substructures in order toeconomically and efficiently drill deep oil wells. Due to the extremeheight of these masts and substructures, which for instance may comprisea total height of about 170 feet, severe problems are presented in thetransportation, erection and subsequent disassembly of the structures.

One type of system previously employed to erect tall masts has requiredhigh gin poles which swing the drilling mast into an upright position bymeans of the traveling block, crown block and drawworks normally used inthe drilling operations on the rig. Such a system is disclosed in US.Patent No. 2,963,124, issued Dec. 6, 1960. The erection of masts withsuch prior systems is often expensive and time consuming. Further,safety hazards arise with these prior systems, as the mast must beindependently supported in an inclined position during erection becausethe traveling block reaches its upper limit of travel before the masthas been fully erected.

Derricks having extremely tall substructures have often requiredmultiple box substructures to attain the desired height, therebyrequiring extensive use of gin pole trucks during erection, in additionto increasing the weight of the system during transportation. Further,after the erection of the high substructure, expensive and bulky truckramps have often been required in order to raise the drawworks andassociated structure up to the drilling floor. Systems have thus beenheretofore developed wherein drawworks may be mounted on the floor ofthe substructure when the substructure is in a lowered position,whereafter the substructure is raised into an elevated position.

Patented Dec. 16, 1969 The mast is then pivoted to a vertical positionand connected to the floor of the substructure for support thereof, US.Patent No. 3,288,151, issued Ian. 11, 1966, discloses such a system.While this type of oil derrick erection system has been found to beadvantageous in some respects, problems still arise due to the fact thatthe extremely heavy drawworks and associated structure are required tobe elevated a considerable distance above ground, thereby necessitatingan extremely strong and heavy substructure. Additionally, the rotarytable and setback loads on such systems are interconnected to thesubstructure and the mast, thereby, thereby imparting vibration andstrain to the mast structure.

SUMMARY OF THE INVENTION In accordance with the present invention, areclining mast is coupled at a pivot to a low profile base. A drawworksis mounted to the low profile base. Spaced apart pulleys are mounted onthe A-frame and three pulleys are mounted on each side of the mast. Acable is anchored at two ends to the A-frarne and threaded over thetopmost of pulleys and thence to the pulleys on the A-frame. The cablethen runs to the middle pulley on the mast and over the lowermost pulleyto the traveling block. A single upward traverse of the traveling blockto the crown block of the system erects the mast.

In accordance with a further aspect of the invention, the set-backstructure is pivotally mounted on the base on the side of the mastopposite the drawworks. When erected, supporting beams extend from theset-back structure through the mast above the base and are secured tothe A-frame. A rotary table is mounted on the beams, wherein the mast isnot subjected to the weight or vibration of the rotary table.

THE DRAWINGS For a more complete understanding of the present inventionand for further objects and advantages thereof, reference may now be hadto the following description taken in conjunction with the accompanyingdrawings, in which:

FIGURE 1 is a side view of the drilling system forming the presentinvention fully erected;

FIGURE 2 is a front view of the system fully erected;

FIGURE 3 is a top view of a base portion of the system; 7

FIGURE 4 is a side view of the base portion system of FIGURE 3 to whichthere has been added extension bases and drawworks;

FIGURE 5 illustrates the structure of FIGURE 4 with the A-frame erected;

FIGURE 6 illustrates the system of FIGURE 5 to which the mast and theraising lines have been attached;

FIGURE 7 is a diagrammatic view of the raising line assembly;

FIGURE 8 illustrates the mast partially erected;

FIGURE 9 illustrates the mast erected and set-back structure in positionfor erection;

FIGURE 10 is a detailed view of the coupling between the A-frame, themast and the set-back structure;

FIGURE 11 is an enlarged view of a portion of the connection between theA-frame and the mast shown in FIGURES 1 and 2;

FIGURE 12 is a sectioned side view of a position of the structure shownin FIGURE 11; and

FIGURE 13 is an enlarged view of a portion of the set-back structureextending through the mast.

THE PREFERRED EMBODIMENT Referring now to FIGURES 1 and 2, the drillingstruc-' ture has been illustrated wherein a mast 10 having legs 11 and12 is pivotally mounted on a base comprised of side boxes 13 and 14 atpivotal axis 15. A drawworks hoist 16 is mounted on two extension boxes17 and 18 which are aligned with and coupled to boxes 13 and 14. Thehoist 16 is provided with a cable 20 which passes over a pulley 21 inthe crown of the mast 10. The cable extends down to a traveling block 22and then over a crown block 23. The traveling block 22 is provided witha supporting hook 24. A racking platform 25 is connected about midwayalong the length of legs 11 and 12.

A catworks unit 39 is mounted on a platform 31 supported on each side bya leg 32, a supporting post 33, and a leg 34. The leg 32 and post 33 arepivoted at point 35 so that during erection they may be coupled to theside box 14 and pivoted to the position shown in FIGURE 1. The leg 34 ispivoted at point 37 so that it may swing during erection into theposition shown in FIGURE 1 and pinned at point 36.

Also included in the drilling structure is a set-back structure 40 whichis coupled to the side boxes 13 and 14 by pins at a pivot axis 41. Theset-back structure includes a platform section 42 in front of the mast10 and is also provided with beams 43 extending through the mast betweenthe legs 11 and 12 to a coupling to the platform 31 immediately abovepivot 37. The platform section 42 is supported by two support structureseach including front legs 44 and 45 pivotally connected at pivot axis41. Each of the support structures also includes rear legs 46 and 47.The two support structures are pinned together at pin point 48 (FIGURE2).

While not shown in FIGURES 1 and 2, the rotary table employed indrilling operations is mounted on the beams 43. By this means, thedrawworks, the catworks and the rotary table are all supported bystructures other than the mast. Further, in accordance with theinvention a coupling between the mast 1t) and the platform 31 is such asto transmit horizontal forces only, so that the sole vertical supportfor the mast 10 is transmitted to the side boxes 13 and 14 through thepins at axis 15. Furthermore, the drawworks hoist 16 is supported at alow level on the structure formed by the side boxes 13 and 14 and servesto maintain the floor for the rotary assembly free from much equipmentwhich is normally located on the upper level rather than at the groundlevel.

FIGURES 3-10 illustrate the sequential steps of erection of the derrickstructure of the present invention. Referring to FIGURE 3, side boxes 13and 14 have been positioned and leveled. A center spreader structure 51)and a rear spreader member 52 are atfixed between the side boxes tomaintain the desired spacing between the boxes. The catworks platform isplaced on the boxes 13 and 14 in a reclining position and a pair of thesupporting posts 33 are pinned to each side box 13 and 14 at pin points35. A catworks spreader 54 is attached between the platforms 31. Each ofthe platforms 3-1 supports a pair of rigid A- frame members 56. A pairof spaced pulleys 57 are carried by two of the A-frame members at theapexes thereof.

FIGURE 4 illustrates a side view of the invention showing the catworksplatform in the reclining position. Extension boxes 17 and 18 (notshown) are next installed and are connected to the rear of boxes 13 and14. Suitable spreaders (not shown) are installed between the extensionboxes 17 and 18 and a drawworks hoist 16 is secured on top of theextension boxes. Legs 34, only one of which is shown, are temporarilyattached at point 58 to each of the legs 32. The legs 34 are pivotallyattached to the platform 31 by pins 37. Projections 60 extend from eachof the boxes 13 and 14.

FIGURE 5 illustrates the erection of the catworks platform from thereclining position indicated by the dotted lines to a vertical positionby a cable 62 passing over a gin pole 64 to a suitable winch (notshown). Platform 31 and the rigidly connected A-frarnes 56, posts 32 andlegs 33 are rotated by the cable 62 about the pivot 35 to the uprightposition shown in FIGURE 5. The pins at points 58 are removed prior toerection of the catworks platform,

.4 and thus the legs 34 swing to a vertical position as the catworksstructure is erected. The bottom ends of the legs 34 are then pulledforward and secured to the projections 61. by pins 36.

FIGURE 6 illustrates the assembly of the mast 10 along the ground infront of the erected catworks structure. The mast 1G is assembled inseveral sections, with the base portion of the mast being first laidupon boxes 13 and 14 and pinned at the pivotal axis 15. The remainder ofthe sections of the mast are then assembled and the traveling block 22is provided with the associated cables in the usual manner. A sheave 66is connected to the platform 31 over which the fast line 20 passesdrawworks 16.

After the mast 10 is assembled as shown in FIGURE 6. mast erection linesare installed in the mast in the manner shown in FIGURE 7. Three pulleys70, 72 and 74 are spaced along each of the mast legs 11 and 12, theoutlines of which are shown, with the pulleys 70 being mounted closelyadjacent the pivotal axis 15. A cable is then anchored at two ends onspaced apart A-frames 56. and threaded over the topmost pulleys 74 todefine the cable segments 76. The cable is then passed to spaced pulleys57 mounted on the A-frames 56 to form cable run segments 77 and thenceto the middle pulleys 72 to form cable run segments '78. The cable thenpasses to the lowermost pulleys 70 located on the mast to form cablesegments 79 and thence to the hook 24 on the traveling block 22 to formcable segments 80. It will be seen that pulleys 70 pass the cable fromthe outside of the legs 11 and 12 into the inside of the legs 11 and 12.As traveling block 22 is pulled upwardly by cables 81 due to thewinching action of the drawworks 16, the cable lengths are lengthenedand the cable lengths 78 are shortened, thereby tending to erect themast 10 as shown in FIG- URE 8.

Mounting of the pulleys 70 closely adjacent to the pivotal axis 15allows the traveling block 22 to be connected to the mast erection cableat the lowermost part of the mast 10. A long traverse of the travelingblock 22 from the bottom of the mast 10 to the crown block of mast 10 isthus provided. This long traverse enables mast 10 to be erected in onlyone upward traverse of the traveling block 22, instead of therequirement of two or more traverses of the traveling block asheretofore required. Additionally, the positioning of the pulleys 70 inthe low position on the mast 10 keeps the weight of the traveling block22 relatively low when the lever arm acting on the mast is short,thereby putting less strain on the erection system and on the maststructure.

Additionally, as is clearly shown in FIGURES 6-8, the drawworks 16 ismounted low on the extension boxes 17 and 18, and therefore is notrequired to be raised high upon the elevated floor of the derrickstructure as in previous systems.

When the mast 10 is finally vertically erected, the mast is pinned tothe platform 31 at pin point 82, as shown in FIGURE 9 FIGURES 11 and 12illustrate in greater detail the connection between platform 31 and themast 10. Projections 83 extend rigidly outward from mast 10 and arereceived between a pair of extension members 84. with the ends ofprojections 83 resting against vertical surfacs on support structures87. A link 85 connects the ends of members 84 together, but is bentupwardly to allow projection 83 to move between the members 84 to bepinned at 82. Members 84 are connected to the platform 31 at the pivotaxis 86, and the members 84 may be swung to a vertical position when notin use. A support structure 87 has slots through which the members 84extend. As best shown in FIGURE 12, the members 84 are normally disposedat a slight angle to the horizontal, with pin points 82 being above axes86, whereby vertical loads on the mast 10 pivot members 84 withoutimposing any vertical loading on the catworks platform.

Hence, the connection between the mast 10 and the platform 31 is suchthat forces are transferred between the mast 1t) and the platform 31which have only horizontal components. The erected platform 31 does notthe then have to be rigidly braced in order to bear any of the weight ofthe mast of loads imposed thereon.

The catworks unit is winched off the back of a truck by the hoist 16onto the center spreaders between side boxes 13 and 14. The travelingblock 22 is then attached to the catworks unit 30 to lift the catworksunit 30 to the position on the platform 31 shown in FIG- URE 9.

The next step in the assembly of the derrick structure is theattachement of the reclining set-back structure to the center spreaderat the pivotal axis 41, as shown in FIGURE 9. The set-back platform 42is then pinned to the set-back support at points 90 and 91. The rotarybeams 43, which may be for instance I-bearns, may then be pinned at 92to the platform 42. The traveling block 22 is then connected to theset-back structure and raises the setback structure about the pivotpoint 41 to the erect position shown in FIGURE 10. Alternatively, theset-back structure may be raised into the vertical position and then therotary beams 43 may be lowered into position and pinned at 92. Therotary beams 43 extend through the mast 10 and are pinned to thecatworks platform 31. FIG- URE 13 illustrates the connection of thebeams 43 in more detail. A projection 93 rigidly extends from theplatform 42 and is pinned to one end of the beams at point 92. Beams 43are in no way attached to the mast 10 and extend between a pair ofextensions 94 (FIG- URES l1 and 13) depending from platform 31. The topflanges of the beams rest on the tops of the extensions 94 and thevertical flanges of the beams are pinned to the extensions by pins 95.

Front spreaders (not shown) are then connected between the front end ofthe boxes 13 and 14 for additional support. A rotary table (not shown)is installed on the rotary beams 43 between the legs of the mast 10.Floor panels (not shown) are then laid across the set-back structure tofill the space between the platform 42 and the catworks platform 31.

From an inspction of the drawings, it will be understood that the rotarytable floor structure is not directly connected to the mast. Thus,vibrations and strain forces are not directly transmitted to the mast.Further, the massive weights of the mast 10 and the rotary table bearupon separate portions of the base structure and are not required to behandled together as in previously developed derrick systems. Theseparate connection of the rotary table in the present derrick structureallows the rotary table to be more strongly braced without adding to theweight of the mast, therefore making the mast lighter and easier toerect.

It is thus understood that the present invention provides a derrickerection structure having a number of advantages. The drawworksstructure is mounted in a low position upon the base, and therefore isnot required to be elevated with the catworks structure. The catworksstructure is relatively light and easy to erect, and truck ramps are notrequired to position the catworks structure on the elevated platform.The mast is erectable in only one traverse of the traveling block, andno temporary support of the mast, shortening of the bridle sling, oradjustment of the length of the traveling block is required duringerection thereof.

When erected, the mast is connected to the catworks structure so thatonly horizontal forces are transmitted therebetween, thereby eliminatingthe necessity of an extremely rigid catworks structure which is requiredto bear e vertical weight of the mast. A set-back structure which iseasily assembled is also provided by the present invention.Additionally, the rotary table structure is not directly connected tothe present mast, thereby eliminating vibration and stress from therotatry table to the mast. The present invention may be easilydismantled and transported in fewer truck loads than previous structuresof similar size.

What is claimed is:

1. A mast erection system for an oil well derrick structure having abase and a reclining mast coupled by a pivot to the base and extendingaway from the base along the ground and a traveling block movable fromthe lower extremity of the mast to a crown block which comprises:

(a) support structure mounted on said base rearward of said pivot,

(b) spaced apart pulleys mounted on said support structure at a levelabove said pivot,

(c) three pulleys mounted on each side of said mast spaced apart alongthe lower region of the mast with the lowermost of said pulleys beingclosely adjacent said pivot, and

(d) cable anchored at two ends and threaded over the topmost of saidpulleys and thence to said pulleys on said support structure, thence tothe middle of said pulleys on said mast and thence to the lowermost ofsaid pulleys and to said traveling block whereby movement of saidtraveling block when engaged by said cable in the region of saidlowermost of said pulleys will erect said mast in one upward traverse ofthe traveling block.

2. The combination set forth in claim 1 whereln a pivotal link isprovided to anchor said mast to said support structure and adapted forthe transfer of forces between said support structure and said masthaving horizontal components only.

3. The combination set forth in claim 1 wherein said mast has a pair oflegs spread apart at said pivot and converging at said crown block withreinforcing structure in said legs confined to provide an unobstructedworking space between said legs, and wherein the surface of sa dlowermost pulley over which said cable leads to said i traveling blockprotrudes into said working space.

5. The combination set forth in claim 1 and further comprising:

(a) set-back structure pivotally connected to said base on the side ofsaid pivot opposite said support structure and having supporting beamsextending through the erected mast above said base to a connection withsaid support structure, and

(b) a rotary table for said mast mounted on said sup porting beams tomaintain said mast free of the weight of said rotary table.

6. In an oil well derrick structure having a base and a reclinable mastwith legs pivoted at spaced points on a pivotal axis onto the base andpinned to a frame above the pivotal axis, the combination whichcomprises:

(a) a set-back structure pivotally mounted on said base on the side ofsaid pivotal axis opposite said frame and having supporting beams abovesaid base extending through said mast and secured to said frame, and

(b) a rotary table mounted on said beams between the legs of said mastwith said mast free of the weight of said rotary table.

7. In an oil well derrick structure wherein a draw-works is mounted on arearward end of a base and a reclinable mast is pivoted at a frontportion of the base, the combination comprising:

(a) a catworks and A-frame platform having back legs rigidly dependingfrom the back of said platform,

(b) the lowermost end of said legs being connectable to a pivot axis onsaid base adjacent the front of said draw-works,

(0) front legs pivotally depending from the front edge of said platformand securable at the lowermost ends thereof adjacent the front portionof said base whereby during erection said platform may be swung aboutsaid pivot axis to a horizontal position and said front 7 legs swungforward and secured at the lowermost ends to securely support saidplatform,

(d) means operated by said drawworks for pivoting said mast to anupright position, and

(e) means for connecting the front edge of said platform to said mastfor transmission of horizontal components of force only between saidplatform and said mast.

8. Oil well derrick structure comprising:

(a) a base having a low profile,

(b) drawwork means mounted on an end portion of said base,

(c) a support platform securable to a central portion of said base at anelevation above said drawwork means,

(d) a mast movable from a horizontal to a vertical position about apivot axis passing through the lower extremity of the mast and throughsaid base on the side of said support platform opposite said drawworkmeans,

(e) a traveling block assembly movable along the length of said mast bysaid drawwork means,

(f) pulleys mounted above said support platform and along the length ofsaid mast,

(g) cable anchored at two ends and threaded over said pulleys to saidtraveling block in a plurality of cable run segments for verticalerection of said mast in one traverse of said traveling block, and

(h) means for connecting said mast when vertical to said supportplatform for transmission of horizontal components of force only betweensaid mast and support platform.

9. The structure defined in claim 8 and further comprising:

reclinable set-back structure pivoted to said base on the end portionopposite said drawwork means,

support beams extending at right angles from said setback structure,

means to move said set-back structure to a vertical position parallel tothe erected mast with said support beams extending through said mast,and

means to connect the ends of said support beams to said support platformwith said mast free of forces on said support beams.

10. The structure of claim 8 wherein said means for connecting said mastto said support platform comprises substantially horizontal link meanspivotally connected to said platform at one end and adapted to bepivotally connected to said mast at the other end.

11. The structure of claim 8 wherein spaced apart pulleys are mountedabove said support platform and three pulleys are mounted along bothsides of the lower portion of said mast, and

said cable is threaded over said pulleys in five cable r-un segments oneach side of said mast to a connection with said traveling block.

12. The structure of claim 11 wherein the lowermost pulley on each sideof said mast is in the region of said pivot axis passing through saidmast and over which said cable passes to a clear zone inside said mast.

References Cited UNITED STATES PATENTS 3,141,653 7/1964 Jenkins 254-l393,228,151 1/1966 Woolslayer et a1. 173-39 3,262,237 7/1966 Jenkins etal. 52ll6 ERNEST R. PURSER, Primary Examiner

